The present invention relates generally to ink jet recording apparatus, and more particularly to such an ink jet recording apparatus with a multi-nozzle type ink jet printing head which allows gradation control of the recording density when ink is ejected from each of a plurality of ink nozzles of the multi-nozzle type ink jet printing head toward a writing surface placed in opposed relation to the printing head.
Various types of ink jet printers have been devised heretofore and one known arrangement is to use a multi-nozzle ink jet printing head of the type wherein printing ink is ejected therefrom toward a writing surface by the aid of an electric field established between two types of electrodes and air-stream supplied from a pressurized air source. Such a multi-nozzle ink jet printing head is illustrated in U.S. Pat. No. 4,555,717, for example. An important problem in such multi-nozzle ink jet printing heads relates to the lack of uniformity in recording thickness or density on a writing surface. This is due to the difference in characteristic between the nozzles of the multi-nozzle ink jet printing head. Thus, a further improvement would be required from the viewpoint of prevention of recording density irregularity.